Draft regulator



July 19, 1949.

F. R. HOAGLIN DRAFT REGULATOR Filed July 2, 1945 FLOYD ATTORNEY II/ a I I I I I l I I l I I I I I INVENTOR. R. HOAGLIN Patented July 19, 1949 DEAF REGULATOR:

Floyd R. Hoaglin, Lansing, Mich, assignor tov Motor Wheel Corporation, Lansing, -Mich.,. a;

corporation of Michigan Application July 2,1945. Ser a No. 61.23.0

7 C aims- 1 This invention relates to improvements in draft regulators for combustion apparatus.

The principal object of the. invention is to provide a draft regulator of. especially economical construction.

Another object of the invention is to provide a draft regulator comprising a frame and damper blade which can be formed from a single blank of sheet metal.

A still further object is to provide a draftregulator in which the pivot bearings for the damper blade pivot shafts as well as the stop means for limiting the movement of the damper blade can be formed from a single blank of sheet metal.

Another object is to provide a pivot bearing and stop bracket that can be quickly and easily attached to the frame of the draft regulator.

These objects will more fully appear in the following specification when read in connection with the accompanying drawings, wherein:

Figure 1 is a front elevational view of'a draft regulator embodying the invention;

Figure 2 is a cross-sectional view taken on substantially the line 22 of Figure 1;

Figure 3 is a fragmentary front elevational view on an enlarged scale of a portion of the draft regulator shown in Figure 1;

Figure 4 is a fragmentary side elevational view of the portion of the regulator shown in Figure 3; and

Figure 5 is a fragmentary cross-sectional View taken on substantially the line 5P5 of Figure 3.

The draft regulator in general comprises a damper blade Ill, an annular frame II, and a balance weight assembly 12. It is attached to the open end of a collar 9 secured to a flue outlet not'shown. The damper blade in and frame I! are pressed from sheet metal. The balance weight assembly I2 is preferably of the type disclosed in the John W. Miller et a1. Patent No. 2,453,098, granted November 2, 1948.

The damper blade I!) is a circular sheet metal member and the frame II is an annular ring. Both blade and frame are formed from a single blank of sheet metal, in order to conserve material, the damper blade being punched from the central part of the blank.

The peripheral portion of the damper blade is substantially flat. However somewhat above the center of the blade the metal is slit at I3. The

portion between the center and radially outer slit is pressed rearwardly, while the portion between the center and radially inner slits is pressed forwardly to form pockets to receive a pair of pivot shafts Hi. The pivot shafts-extend beyond the rim of the blade and are pivoted on the frame I l as will more fully appear presently.

The blade. is provided with a forwardly pressed recess 15 above the pivotaxis. In the center of th recess is an aperture to receive the balance weight assembly 12.,

The balance weight assembly comprises a hub IS, a shaft. l'l, a we1ght.l8 and a knob [9. The hub has. abearin therein to rotatably receive the. shaft [1. The bearing is providedwith a helical groove 20 which cooperates with a spring pressedbutton 2| in the shaft whereby rotation of the. shaft causes an axial movementof the Weight [8, shaft 11 and knob l9. This movement changes the center of gravityof, the entirev assembly and varies the resistance ofthe blade to swingingabout its pivot. This effect is. well known and need not be further described.

The frame II, as above mentioned, is formed from the, same sheet netal blank from which the blade H! is pressed. The frame isan annulus of generally Z-shaped cross-section. It has an outer flange 22 whichabuts the end of collar 8, a cylindrical portion 23 which telescopes within the collar 5, and a radial flange 24 W thin whichthe damper blade is hung, The flange 24 is pressed rearwardly-at two places toform recesses .25, the purpose of which will appear presently. Substantially centrally of the recesses 25.slots 26 are cut. Two one piece brackets 21 are attached to the frame to provide pivot shaft bearings and stops for limiting the pivotal movement of the damper blade. Thebrackets are stamped from sheet metal. They, are similar in shape butreversed. from each other, Each bracket has a bearing portion 28 and apair of stop portions 29 and 30 at right angles to the bearin portion. Bearing portions 28 are provided with oval bearing.

apertures 3| therein. Attaching lugs 32. are formed on one corner of each bearing portion.

Stop portions 2 9.and 30 are formed to the configuration shown in Figure 3. Stop portions 29 are offset forwardly from .thestop portions 30 as shown in Figure 4. The upper edges of stop portions. 29. are located slightly above the bearing both brackets to the frame, the bearing shafts on the damper blade are inserted in the bearing apertures 3 I. Then when the brackets are riveted to the frame the entire assembly of damper blade, frame, and brackets are held in proper relationship to each other.

The centers of the oval bearin apertures 3! are located in the plane of the flange '24 on the frame. This is permitted by the recesses 25 which are formed in the frame. Also the oval shape of the bearing apertures reduce friction between the shafts l4 and bearing surfaces, because the shafts can roll on the lower edges of the apertures 3| instead of the usual rotating and sliding motion characteristic of cylindrical bearings.

The operation of draft regulators of this character are well known and need not be described in detail. Suffice it to say that as the area of the part of the blade I below the pivot axis is greater than the area of the part above the axis, any difference in pressure between the air inside of the flue and the air outside thereof causes a tendency for the damper blade to swing on its axis. If the air pressure inside the flue is lower than that outside, the lower part of the damper swings inward to admit more air to the flue. Variations in that pressure difference, normally spoken of as draft, causes the damper blade to open and close, maintaining a constant draft. The draft may be regulated. by adjusting the weight toward and away from the plane of the blade.

The upper edge of stop 29 limits inward movement of the lower part of the damper blade, because when the blade swings through slightly less than 90" from its vertical position it contacts stop 29. Stop 38 prevents any movement in the opposite directionof the damper from its vertical position, which might be occasioned by a downdraft in the flue.

From the foregoing it will be seen that the present invention provides a very simple, economical, and easily fabricated draft regulator. There is little wasted material. the only waste occurring in forming the brackets 21 and the blank from which the frame and damper blade are formed. Furthermore. the one piece brackets 2! require little material themselves and are very easily assembled.

The scope of the invention is indicated in the appended claims.

I claim:

1. A draft regulator comprising a frame having a substantially plane portion with an opening therein said plane portion having a pair of apertures therein on opposite sides of said opening, a damper blade substantially filling said opening, means pivotally connecting said damper blade to said frame comprising journal means on said blade, a pair of brackets, each of said brackets having a bearing portion at right angles to said blade and receivin said journal means, said brackets having integral tongues inserted in said apertures for attaching said brackets to said frame. said brackets also having stop means thereon engageable with said blade for limiting the pivotal movement thereof in both directions.

2. A draft regulator comprising a frame having a substantially plane annular portion with an opening therein for the reception of a damper blade, said plane portion having axially opening recesses therein on oposite sides of said opening and apertures in the bottoms of said recesses, a damper blade in said opening, and means for pivotally mounting said damper blade in said frame comprising a pair of one piece brackets having bearin flanges at right angles to the plane of the frame and received in said apertures, said bearing flanges having shoulders thereon engaging axially opposite sides of said frame, said brackets having stop means thereon parallel to the plane of the frame and engageable with the blade for limiting the pivotal movement of the damper blade in both directions.

3. A draft regulator comprising a frame having a substantially plane portion with an opening therein, a damper blade substantially filling said opening when said blade is in closed position, means pivotally connecting said damper blade to said frame comprising journal means on said blade, and a pair of brackets attached to said frame, each of said brackets having a bearing flange receiving said journal means, each of said brackets having stop means thereon engageable with said blade, said stop means comprising a generally Z-shaped section of said bracket having one leg of said Z-shaped section parallel to, and attached to, the plane portion of said frame and overlapping said blade at one side of said journal means, for limiting the movement of said blade in one direction, the other leg of said Z-shaped portion overlapping said blade in the region of said journal means and spaced from said blade, when the blade is in the plane of said plane portion, for limiting movement of the blade in the opposite direction.

4. A draft regulator comprising a frame having a substantially plane annular portion with an opening therein for the reception of a damper blade, a damper blade in said opening, said frame having a pair of apertures therein for the reception of bearing brackets, and means for pivotally mounting said damperblade in said frame comprising a pair of one piece brackets having bearing flanges at right angles to the plane of the frame and received in said apertures, said bearing flanges having shoulders thereon engaging axially opposite sides of said frame, said brackets having stop means thereon parallel to the plane of the annular portion of the frame and engageable with the blade for limiting the pivotal movement of the damper blade in both directions.

5. A draft regulator comprising a frame having a substantially plane annular portion with an opening therein for the reception of a damper blade, a damper blade in said opening, said frame having a pair of apertures therein for the reception of bearing brackets, and means for pivotally mounting said damper blade in said frame comprising a pair of one piece brackets having bearing flanges at right angles to the plane of the frame and received in said apertures, said bearing flanges having shoulders thereon engaging axially opposite sides of said frame, said brackets having stop means parallel to the plane portion of the frame extending from said flanges in a direction circumferentially of the frame and fixedly secured thereto.

6. A draft regulator comprising a frame having a substantially plane portion with an opening therein, said plane portion having a pair of apertures therein on opposite sides of said opening, a damper blade substantially filling said opening, said blade being substantially in the plane of said plane portion when closing said opening, and means pivotally connecting said damper blade to said frame comprisingv journal means on said blade and a pair of brackets, each of said brackets having a bearing portion at right angles to said blade and receiving said journal means, said brackets having integral shouldered tongues inserted in said apertures for attaching said brackets to said frame, the shoulders on said tongues being positioned on one side of said plane portion and the bearing portion on the opposite side of said piane portion of the frame.

7. A draft regulator comprising a frame having a substantially plane annular portion with an opening therein for the reception of a damper blade, a damper blade-in said opening, the plane portion of said frame having a pair of apertures therein for the reception of bearing brackets, and means for pivotally mounting said damper blade in the plane annular portion of said frame comprising a pair of one piece brackets having bearing flanges at right angles to the plane of the frame and received in said apertures, said bear- REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 15 2,167,182 Morrow July 25, 1939 2,194,608 Miller Mar. 26, 1940 2,297,757 Field Oct. 6, 1942 

